Don't try to spot out the white areas with a single large application.

Instead, fill in the white areas with lots and lots of almost imperceptible little dots of dye.

Keep the pens moving as you lightly touch the area over and over - a figure 8 pattern of small movements works well.

It is generally better to spot too little.

The pens work well once you get used to them - and if you apply the tone this way the pens will last a very long time.

Matt

“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2